<template>
	<view>
		<view class="scroll-view-container">
			<!-- 左侧的滑动区域 -->
			<scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
				<block v-for="(item,i) in cateList" :key="i">
					<view :class="['left-scroll-view-item',i === active?'active':'']" @click="activeChanged(i)">{{item.cat_name}}</view>
					
				</block>
				
			</scroll-view>
			
			<!-- 右侧滑动区域 -->
			<scroll-view scroll-y="true"  :style="{height: wh + 'px'}" :scroll-top="scrollTop">
				<view class="cate-lv2" v-for="(item2,i2) in cateLevenl2" :key="i2">
					<!-- 二级分类标签 -->
					<view class="vate-lv2-title">
						/{{item2.cat_name}}/
					</view>
					<!-- 动态渲染三级分类 -->
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
							<!-- 三级分类的图片 -->
							<image :src="item3.cat_icon"></image>
							<!-- 三级分类文本 -->
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
				
				// 当前设备可用的高度
				wh:0,
				cateList:[],
				active:0,
				
				//2级分类
				cateLevenl2:[],
				
				scrollTop:0
			};
		},
		onLoad() {
			//获取当前屏幕可用的高度
			const sysInfo = uni.getSystemInfoSync()
			this.wh = sysInfo.windowHeight,
			
			this.getCateList()
		},
		methods:{
			
			//获取分类列表的数据
			async getCateList(){
				const {data:res}  = await uni.$http.get('/api/public/v1/categories')
				if(res.meta.status !== 200) return uni.$showMsg()
				
				this.cateList = res.message
				
				//为二级分类赋值
				this.cateLevenl2 =  res.message[0].children
			},
			
			activeChanged(i){
				this.active  = i
				
				
				//重新为二级分类赋值
			    this.cateLevenl2 = this.cateList[i].children;
				
				this.scrollTop = this.scrollTop === 0 ? 1 : 0;
			},
			
			gotoGoodsList(item){
				uni.navigateTo({
					url:'/subpkg/goods_list/goods_list?cid=' + item.cat_id
				})
			}
		}
	}
</script> 

<style lang="scss">

.scroll-view-container{
	display: flex;
	
	.left-scroll-view{
		width: 120px;
		
		.left-scroll-view-item{
			background-color: #F7F7F7;
			line-height: 60px;
			text-align: center;
			font-size: 12px;
			position: relative;
			
			&.active{
				background-color:#FFFFFF;
				
				&::before{
					content:'';
					display: block;
					width: 3px;
					height: 30px;
					background-color: #C00000;
					position: absolute;
					top: 50%;
					left: 0;
					transform: translateY(-50%);
				}
			}
		}
	}
	
	.vate-lv2-title{
		font-size: 12px;
		font-weight: bold;
		text-align: center;
		padding: 15px 0;
	}
	
	.cate-lv3-list{
		display: flex;
		flex-wrap: wrap;
		
		.cate-lv3-item{
			width: 33.33%;
			display: flex;
			flex-direction: column;
			justify-content: center;
			align-items: center;
			image{
				width: 60px;
				height: 60px;
			}
			text{
				font-size: 12px;
			}
		}
	}
}


</style>
